Cash sitting in a brokerage account or a business banking relationship rarely sits still overnight. A sweep moves it automatically, and where it goes changes its legal character.
The sweep is an automated nightly transfer
At the close of business, uninvested cash above any threshold is moved into a designated destination, and it is moved back when needed to fund a transaction.
The account holder sees a single balance and generally does not observe the movement, which is why sweeps go unnoticed until a statement footnote explains them.
The arrangement exists because idle cash is unproductive for both parties, and automating the movement removes the need for anyone to act daily.
Destinations differ in what backs them
A bank deposit sweep places the cash on deposit at one or more partner banks, where it is a deposit liability of those banks.
A money market fund sweep buys shares in a fund. The holder owns fund shares rather than a deposit, and the fund holds short-term instruments.
The distinction matters because deposit insurance applies to bank deposits within its limits and rules, while fund shares are securities with a different protection framework entirely.
Multi-bank programs exist for a reason
Deposit insurance limits apply per depositor per insured bank, so a large cash balance at one institution can exceed the covered amount.
Sweep programs that distribute cash across several partner banks are structured around that arithmetic, keeping amounts at each institution within the applicable limits.
The program's disclosure lists the participating banks, and an account holder who already banks with one of them may hold more there than they realize.
Default options are set by the provider
Brokerages designate a default sweep destination, and the yield on the default is frequently lower than on alternatives the same firm offers.
Moving cash into a different arrangement is usually possible but requires the account holder to act, since the default persists until changed.
Firms disclose the arrangement and any compensation they receive from it, though the disclosure appears in account documents rather than in the balance display.
Where sweeps complicate records
A statement may show cash and swept balances as separate lines, or as a single figure, depending on the provider and the destination type.
Automated aggregation tools sometimes read both, producing an apparent doubling of the cash position that resolves once the sweep line is identified.
For anyone reconciling accounts, the reliable approach is to identify which line represents the actual claim and which is a presentation of the same money.